(1) Field of the Invention
The invention relates to a method of dicing a semiconductor wafer into small pieces (chips).
(2) Description of the Related Art
There has been known a method of dicing a semiconductor wafer into chips. According to the method, a back face of the semiconductor wafer a surface of which is protected with a protective tape is ground (back grinding) to a desired thickness, and the resultant semiconductor wafer is mounted on a dicing ring in a state where the back face thereof is adhered to an adhesive tape. Subsequently, the protective tape on the surface of the wafer is separated and, after that, parting lines as narrow trenches in the vertical and horizontal directions are formed with a diamond cutter or the like along scribing lines in the surface of the semiconductor wafer. After that, a pressing member such as a roller is pressed against the back face of the adhesive tape to make a bending stress concentrated on the parting lines, thereby parting the semiconductor wafer into chips. Finally, the adhesive tape is drawn radially to extend the clearances among the chips.
There has been also developed a technique which suppresses generation of dust accompanying formation of parting lines by forming a modified part in a semiconductor wafer with a laser to thereby obtain a parting line as compared with the case of using a diamond cutter (see JP-A 2003-33887).
In the conventional dicing technique, however, at the time of dicing a semiconductor wafer along parting lines formed in any of various modes, an external force is applied to the back side of the adhesive tape adhered to the semiconductor wafer to make the bending stress concentrated on the parting lines. There is consequently a possibility that the pattern on the surface of the wafer is damaged due to occurrence of cracking, adhesion of dust generated by the dicing to the surface of a chip, or the like.